The interaction of the human immunodeficiency virus type 1 (HIV-1) nucleoprotein complex with the cell nuclear import machinery is necessary for viral replication in macrophages and for the establishment of infection in quiescent T lymphocytes. The karyophilic properties of two viral proteins, matrix (MA) and Vpr, are keys to this process. Here, we show that an early step of HIV-1 nuclear import is the recognition of the MA nuclear localization signal (NLS) by Rch1, a member of the karyopherin… CONTINUE READING